v0.0.23

v0.0.23: groundwork for making number_of_sprinklers, flow and area configurable using options flow as well (#27). daily bucket delta is now not the most recent bucket value as reported by the hourly sensor but the average of the values collected. this assumes the daily bucket is calculated at least once per day. This a step towards enabling use of weather stations (#12). Also adding some work for fixing #26.